Driving mechanism for bicycles.



Patented June 27, I899.

A. F. A. RUXENDDRFF. DRIVING MECHANISM FOR BICYCLES.

(Application filed Dec. 24, 1897. Renewed Apr. 15, 1899.)

(No Model.)

wiimeooao c uonms PETERS co. FHUTO-UTHO. WAS

UNITED STATES PATENT QFFICE.

AXEL FREDRIK ABRAHAMSON ROXENDCRFF, OF STOCKHOLM, Sl/VEDEN.

DRIVING MECHANISM FOR BICYCLES.

SPECIFICATION forming part of Letters Patent No. 627,881, dated June 27, 1899.

Application filed December 24,1897. Renewed April 15, 1899. Serial N0.'713,175. (No model.)

Too whom it may concern:

Be it known that I, AXEL FREDRIK ABRA- HAMSON ROXENDORFF, mechanical engineer,

a subject of the King of Sweden and Norway,

7 and a resident of Stockholm, Sweden, have Exertion of Power in Bicycles and other Vehieles, (patented byme in the following countries: Sweden, No. 8,392, September 11, 1896; France, No. 263,175, January 18, 1897; Great Britain, No. 6,338, March 10, 1897; Italy,Vol. XXXII, No. 44,064, and Vol. LXXXVL'NO. 229, March 9, 1897; Belgium, No. 126,861, March 9, 1897, and Austria, No. 47/2,827, July 28, 1897,) of which the following is a specification, reference being had therein to the accompanying drawing.

This invention has for its purpose to secure to me the exclusive right to certain constructions of bicycles and other vehicles in which the driving mechanism consists of oscillating treadles to which are secured chains or other driving means having one end fastened to a friction or ratchet coupling acting on the hub of the driving-wheel, one such coupling being located on each side, while the other'end of the chain D is fastened to the treadle, said driving means passing over a block or pulley E, movably attached to the frame. The center of oscillation of the treadle coincides with the center of the driving-wheel, or at least lies near it.

The motionof the oscillating treadles is transferred to the hub of the driving-wheel, on which act two friction or ratchet couplings F, one on each side, on which the driving means are wound and unwound. Byde pressing the treadle on one side motion is transmitted to the coupling F, which rotates the driving-wheel forward, while the driving means belonging to the other treadle is simultaneously wound onto its corresponding coupling by a special mechanism, raising said treadle, which at that time is inactive. The leverage is varied by moving the block or disk E longitudinally with reference to the frame or between the extremities A and on said tube for producing the leverage desired. By'this method the angle a between the treadle and the driving meansisincreased' or decreased, and consequently the pull on the driving means (denoted by the force a or a in the drawing) will vary in amount accord ing to the size of the angle a. A uniform force 12 is, however, in' this case exerted in the vertical direction by the foot of the rider. (See the parallelogram of forces in the draw ing.) If the block E be shifted between A and A it is evident that the tension in the chain will vary between a and a, In the case when the block E is placed in the position A the force a acting on the chain will be smaller, but the velocity greater than if these parts be placedat A in which case the force a will be greater, but the velocity smaller. The block E slides on an elliptic are E, having a focus at the center of the driving-wheel, while its other focus coincideswith the point of attachment of the chain on the treadle when the latter is in its middle position. The treadle consequently has the same middle position no matter where the block E is located between A and A In the drawing the center of oscillation of the treadle is located at the center of the driving-wheel. It is evident, however, that the former can be located at some distance from the latter.

Having now described my invention, what I claim as new, and desire to secure byLetters Patent, is

In a bicycle or similar vehicle, the combination with the frame, the driving-wheel, the hub and the axle, the coupling adapted to engage with said hub, and the elliptic bar secured to the frame, of the fulcrum bar or bar and the chain connected with said coupling and directly connected to the treadle, and passing over said disk or block, substantially as described.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

AXEL FREDRIK ABRAHAMSON ROXENDORFF.

Witnesses:

ERNST SVANQVIST, E. HERMANSSON. 

